Device for screwing and crimping a cap on a neck

ABSTRACT

A device including a rotating capping head with axial displacement, characterized in that the head is provided with means for screwing a cap on the neck, and means for crimping the cap beneath a crimping ring. The axial displacement includes a first axial displacement of the head activating the screwing means and a second axial displacement of the head activating the crimping means, so as to produce successively, and in one single axial displacement of the head, a screwing step and a crimping step constituting the capping process. The inventive device enables the cap to be screwed and crimped in one single step.

FIELD OF THE INVENTION

The invention relates to the domain of capping of receptacles,particularly bottles, and typically screwing and crimping screw sealingcaps on bottles with threaded necks.

STATE OF THE ART

Caps are usually crimped using a capping head with mobile wheels thatoperates according to the principle described in French patent No. 978537.

The essential elements of the crimping head include particularly:

-   -   a spring ejector provided with a profiled end piece with axial        displacement due to a slide fixed to the frame of the capping        machine,    -   a rotating ring (rotated by means not shown) with a slide as hub        and on which rods are fixed, the end of each rod being fitted        with a wheel free to rotate axially,    -   springs acting on the set of rods such that the wheels apply a        radial pressure on the cap while actually crimping, or on the        profiled end piece during the crimping cycle phase,    -   guide means.

When crimping an outer cap, the rotating ring, the rods and the wheelsare all rotating, and while the end piece presses on the head of thecap, there is a relative displacement (axial) of the rotating ring, rodsand wheels with respect to the assembly formed by the ejector and theskirt of the cap: gradually, the wheels that were initially bearing onthe profiled end piece come into contact and bear on the skirt of thecap and crimp it.

The inventors have already improved existing crimping heads severaltimes, firstly by modifying the profile of the wheels as described inFrench patent No. 2 469 379, and also by varying the hardness of thewheels, as described in French patent No. 2 675 495, and finally byvarying the number and configuration of the wheels as described inFrench patent No. 2 710 905.

Screwing heads are also known.

Problems that Arise

Up to now, bottles with threaded necks with a metallic screw cap weresealed in two passes or two steps, with two different items ofequipment:

-   -   a cap screwing step using a screwing head,    -   then a crimping step using a crimping head.

This invention is intended to perform the two screwing and crimpingoperations in a single step and with a single item of equipment, so asto reduce the capping investment, in other words the cost of cappingequipment or devices, to reduce the capping time, and to reduce the sizeof capping equipment.

Consequently, the inventors have developed a device for performing acomplete screwing and crimping operation on the sealing cap, in a singlepass.

DESCRIPTION OF THE INVENTION

According to the invention, the capping device for a neck of areceptacle with an axis of symmetry, typically a bottle, comprising anupper threaded portion with height Hf provided with at least one threadwith N turns and a lower portion or crimping ring, using a screw sealingcap provided with a head and a crimpable skirt, typically metallic,comprises a capping head capable of rotating at a rotation speed Ω usinga rotation means, about an axis of rotation with the said axis ofsymmetry, and with axial displacement so as to move the said head closerto the said neck typically fixed in the axial direction, during the saidcapping operation due to an axial displacement means, and ischaracterised in that the said head is provided with a means of screwingthe said cap to the said upper threaded portion of the said neck, and ameans of crimping the said skirt under the said crimping ring, the saidaxial displacement comprising a first axial displacement of the saidhead activating the said screwing means and a second axial displacementof the said head activating the said crimping means, so as to havefirstly a screwing step and secondly a crimping step forming the saidcapping operation, or in a single axial displacement of the said head.

Thus, with the device according to the invention, a single axialdisplacement of the head is sufficient to successively screw and then tocrimp the cap which solves the problems that arise since a single headis sufficient where two heads and two distinct items of equipment werenecessary using standard equipment according to the state of the art.

DESCRIPTION OF THE FIGURES

All the figures relate to the invention.

FIGS. 1 to 6 b show diagrammatic views or sections through a verticalplane passing through the axis of rotation (20) of the capping head (2)and the axis of symmetry (71) of the neck (70) to be sealed.

FIG. 1 is a diagrammatic view of the capping device (1).

FIGS. 2 to 5 are left half-views of the capping head (2) during thedifferent cap fitting phases, as the head (2) is lowered with respect ofthe neck (70) to be sealed:

FIG. 2 shows the head (2) before the beginning of screwing of thesealing cap (8) on the neck (70),

FIG. 3 shows the head (2) at the end of screwing of the cap (8), butbefore compression of the seal (81) in the cap,

FIG. 4 shows the head (2) after compression of the seal (81) and thebeginning of tipping of the crimping arm (40),

FIG. 5 shows the head (2) at the end of crimping.

FIGS. 6 a and 6 b relate to the head that was made, FIG. 6 a being aview of the major part of the head (2), while FIG. 6 b is an enlargedview of the lower part of the head.

FIGS. 7 a to 7 c show diagrams related to axial displacements of thehead or its different parts.

FIG. 7 a shows displacements (ordinate) of the different parts of thehead during a single cycle (abscissa), namely as the head is lowered andthen lifted once.

FIG. 7 b diagrammatically shows several cycles (3 cycles) composed oflinear portions, while in FIG. 7 c the head displacement is sinusoidal.

DETAILED DESCRIPTION OF THE INVENTION

According to the invention, during the said first displacement, the saidscrewing means can rotate the said cap (8) with respect to the said neck(70) with a rotation speed of the said cap (8) typically close to thesaid rotation speed Ω of the said head (2).

As soon as the bearing part (6) comes into contact with the cap to bescrewed, it drives it in rotation at speed Ω.

This contact may correspond to a predetermined axial force and, asillustrated particularly in FIGS. 2 and 3, to achieve this the saidscrewing means may comprise a means, typically a spring R0 (60) applyinga force F0 on the said head (82) of the said cap (8) typically varyingfrom 20 N to 150 N, during all or some of the said screwing step.

According to the invention, the said crimping means may include at leasttwo arms or lifting beams (40), each arm (40) carrying a crimping roller(41) at its lower end, articulated so that it can be brought closer tothe said neck (70) during the said crimping step and moved away from thesaid neck (70) during the said screwing step.

As shown particularly in FIGS. 3 to 5, the said head (2) may include ameans, typically a spring R2 (42) for applying a force F2 on the saidhead (82) of the said cap (8), typically varying from 500 N to 1500 Nafter the said screwing step and during all or some of the said crimpingstep.

As can be seen in FIG. 4, the said means for applying the said force F2may typically be activated before the said rollers (41) are applied incontact with the said skirt in order to crimp the said skirt (80), so asto axially compress the said cap (8) in contact with the said neck (70)and its sealing ring, particularly when the said cap (8) comprises acompressible seal (81) to be compressed before the crimping step inorder to seal the said cap (8) on the said neck (70).

According to one embodiment of the invention, the said head (2) maycomprise:

-   -   a) a support C3 (3), typically cylindrical, solidarised to a        fixed frame (10), capable of turning about the said axis of        rotation (20) with the said rotation speed Ω typically        predetermined and possibly constant, and moving in the axial        direction with respect to the said neck (70) with an axial        displacement D3,    -   b) a coaxial tubular body C2 (4) internal to the said support C3        (3), but capable of moving axially with respect to the said        support C3 (3) with an axial displacement D2, the said support        C3 (3) comprising a lower stop (30) to limit the axial        displacement of the said tubular body C2 (4) and applying a        force F2 on the said tubular body C2 (4), typically using a        spring R2 (42),    -   c) a central body C1 (5), coaxial with the said tubular body C2        (4), typically hollow, solidarised to the said tubular body C2        (4) for the said displacement D2 typically by means of a set of        bearings, typically needle bearings (45), the said tubular body        C2 (4) forming a hub for the said central body C1 (5) acting as        an axle,    -   d) a means for partial coupling of the said tubular body C2 (4)        and the said central body C1 (5) in rotation, rotation of the        said tubular body C2 (4) only causing a rotation of the said        central body C1 (5) during the said screwing step, rotation of        the said central body C1 (5) possibly being interrupted by the        development of an opposing torque C at the end of screwing,    -   e) the said central body C1 (5) comprises a bearing part C0 (6)        that will cause rotation of the said cap (8) and move axially        with respect to the said central body C1 (5) with a displacement        D0 typically corresponding to the height of the said threaded        portion (700) of the said cap (8), an upper stop (51) for the        said bearing part (6) and a spring R0 (60) applying a force F0        on the said bearing part C0 (6) so as to provide coupling of the        said head (2) through the said bearing part C0 (6) and the said        cap (8) in rotation, and to form the said screwing means,    -   f) the said arms or lifting beams (40) of the said crimping        means are axially fixed to the said tubular body C2 (4) and can        be rotated due to a secondary rotation axis (44) typically fixed        to the said tubular body C2(4).

The said crimping means may include a cam (32) axially fixed to the saidsupport C3 (3), each of the said typically rigid arms (40) comprising anupper part (400) typically provided with a caster or a wheel or asliding pad (401), and a roller support arm (402) supporting the saidroller (41), such that the said second displacement causes a temporarycooperation of the said cam (32) and the said wheel or pad (401),bringing the said roller (41) closer to the said neck (70) for saidcrimping.

According to one embodiment of the invention illustrateddiagrammatically in FIG. 1, the said support C3 (3) of the said head (2)may be solidarised to an arm (12), typically horizontal, and is free inrotation with respect to the said arm (12), the said support C3 (3) andthe said arm (12) respectively forming an axle/hub assembly, the saidarm (12) possibly acting as a support for a motor forming the saidrotation means (13) capable of driving the said support C3 (3) inrotation.

The said arm (12) and the said fixed frame (10) may cooperate, typicallyusing a vertical column (14) so as to assure the said axial displacementD3 of the support C3 (3) by translation of the said arm (12) in avertical plane, typically by means of an auxiliary motor (11) acting asan axial displacement means.

But according to another embodiment of the invention (not shown in anyfigure), the said arm (12) may be placed onboard a rotary turret andform part of a set of n capping heads (2), where n typically varies from2 to 12, the supports C3 (3) being engaged to a central gearwheel torotate the said supports C3.

According to the invention, the said partial rotational coupling meansof the said tubular body C2 (4) and the said central body C1 (5) may bea magnetic or electromagnetic coupling, typically by means of facingmagnets (43, 50) supported by the said tubular body C2 (4) and the saidcentral body C1 (5). These facing magnets are typically chosen such thatthe torque applied on the cap is equal to not more than 80% of the valueof the limiting torque corresponding to irreversible deformation ordestruction of the cap.

It is advantageous if at the end of the screwing step, the said bearingpart C0 (6) is capable of coming into contact and stopping in contactwith the said upper stop (51) so that the said central body C1 (5) andthe said tubular body C2 (4) can transmit the said force F2 to the head(82) of the said cap (8).

The rotation speed Ω and displacement speed V of the said head (2)during the said first displacement may be slaved so as to satisfy therelation V=Hf.Ω/N so as to synchronise rotation of the said cap (8) andthe lowering speed onto the neck (70) during the said screwing step,typical values of Hf, Ω and N being 5 mm to 20 mm for Hf, 150 rpm to 500rpm for Ω, 0.5 to 5 for N, with the total number of rotations varyingfrom 10 to 25. Thus, there is no risk of deformation of the threads ofthe caps.

Another purpose of the invention is a method of capping a bottle usingthe capping device (1) according to the invention using a capping head(2) screwing and crimping a screw cap (8) on the threaded neck (70) ofthe said bottle or receptacle (7) and in which the said bottle (7)having firstly being brought facing the said head, typically byhorizontal step by step displacement, or possibly continuousdisplacement, the said bottle (7) and alignment of the said rotationaxis (20) and the axis of symmetry (71) and held still for a time Tcorresponding to one capping cycle, the said head is subjected to acyclic movement with duration T with respect to the said neck (70)typically including lowering of the said head from a high point to a lowpoint, with a lowering time Td of the said head during which the saidcap was firstly procured and placed on the said neck, the said screwingis carried out first during a time Tdv followed by the said crimping fora time Tds, the said lowering time Td being approximately equal to thetime necessary to perform the said first and second displacements,followed by a rise time Tr of the said head, the said bottle after beingcapped being displaced and replaced by another bottle to be cappedtypically when the said head is at the said high point.

FIG. 7 a diagrammatically illustrates the different displacements(ordinates) as a function of time during a cycle T (abscissa).

In this process, the said cyclic movement of the said head (2) may be asinusoidal movement typically obtained by cooperation of a connectingrod and a crank, as illustrated in FIG. 7 c. It may possibly be acontinuous circular movement typically obtained using a cam.

The said cyclic movement of the said head may be a movement composed oflinear parts at constant speed, typically obtained with hydraulic jacksas illustrated in FIG. 7 b. In this case, the rising time Tr may beshorter than the lowering time Td, and typically less than half as long.

Example Embodiment

FIGS. 6 a and 6 b form an example embodiment of a head (2) according tothe invention, FIGS. 2 to 5 being more diagrammatic and intended toexplain operation of the head (2) represented in FIGS. 5 a and 6 b.

Marks shown in FIG. 2 have not been repeated in FIGS. 3 to 5, to avoidmaking FIGS. 3 to 5 unnecessarily more congested.

ADVANTAGES OF THE INVENTION

The invention can solve the problems that arise and perform the screwingand crimping operations in a single step and with a single item ofequipment.

Furthermore, although the device according to the invention is slightlymore expensive than a screwing device or a crimping device, issignificantly less expensive than the combined investment cost of ascrewing device and a crimping device. The same is true for themaintenance cost of the device according to the invention.

The inventors have also observed that the device according to theinvention can increase production rates.

Finally, the device according to the invention halves the floor spaceoccupied by separate screwing means and capping means.

LIST OF REFERENCES

-   -   capping device . . . 1        -   Fixed frame . . . 10        -   Axial displacement means (aux. motor) . . . 11        -   Horizontal arm . . . 12        -   Means of rotation (motor) of 2 . . . 13        -   Vertical column . . . 14    -   Capping head . . . 2        -   Rotation axis . . . 20    -   Support C3 . . . 3        -   Lower stop . . . 30        -   Coupling of 3 and 4 in rotation . . . 31        -   Cam cooperating with 401 . . . 32    -   Tubular body C2 . . . 4        -   Arms or lifting beams . . . 40            -   Upper part . . . 400            -   Wheel or pad . . . 401            -   Roller support arm . . . 402            -   Crimping spring . . . 403            -   Arm return spring 40 . . . 404        -   Crimping roller . . . 41        -   Spring R2 . . . 42        -   Partial coupling in rotation (magnets) . . . 43        -   Secondary rotation axis . . . 44        -   (Needle) bearings between 4 and 5 . . . 45        -   Centring device . . . 46    -   Central body C1 . . . 5        -   Partial coupling in rotation (magnets) . . . 50        -   Upper stop . . . 51        -   End piece adaptable to the neck . . . 52    -   Bearing part C0 . . . 6        -   Spring R0 . . . 60    -   Bottle, receptacle . . . 7        -   Neck . . . 70            -   Threaded upper portion . . . 700            -   Lower portion or ring . . . 701        -   Axis of symmetry . . . 71    -   Sealing cap . . . 8        -   Crimpable skirt . . . 80        -   Compressible seal . . . 81        -   Head . . . 82    -   Bottle, receptacle support . . . 9

1. Capping device (1) for a neck (70) of a receptacle (7) with an axisof symmetry (71), typically a bottle, comprising a threaded upperportion (700) with height Hf provided with at least one thread with Nturns and a lower portion or crimping ring (701), using a screw sealingcap (8) provided with a head (82) and a metallic crimpable skirt (80),the said device (1) comprising a capping head (2) capable of rotating ata rotation speed Ω using a rotation means (13), about an axis ofrotation (20) common with the said axis of symmetry (71), and with axialdisplacement so as to move the said capping head (2) closer to the saidneck (70) typically fixed in the axial direction, during the saidcapping operation, characterised in that: a) the said capping head (2)is provided with a means of screwing the said cap (8) to the saidthreaded upper portion (700) of the said neck (70), and a means ofcrimping the said skirt (80) under the said crimping ring (701), thesaid axial displacement comprising a first axial displacement of thesaid capping head (2) activating the said screwing means and a secondaxial displacement of the said capping head (2) activating the saidcrimping means, b) the said screwing means rotates the said cap (8) withrespect to the said neck (70), during the said first displacement, thesaid screwing means comprising a means applying a force F0 on the saidhead (82) of the said cap (8) varying typically from 20 N to 150 N,during all or part of the said screwing step, so as to have a screwingstep and a crimping step forming the said capping head (2).
 2. Deviceaccording to claim 1 in which the said screwing means rotates the saidcap (8) with a rotation speed typically close to the said rotation speedΩ of the said capping head (2).
 3. Device according to claim 2, in whichthe said screwing means comprises a spring R0 (60) applying the saidforce F0 on the said head (82) of the said cap (8).
 4. Device accordingto claim 1, in which the said crimping means includes at least two armsor lifting beams (40), each arm (40) carrying a crimping roller (41) atits lower end, articulated so that it can be brought closer to the saidneck (70) during the said crimping step and moved away from the saidneck (70) during the said screwing step.
 5. Device according to claim 1,in which the said capping head (2) includes a means, typically a springR2 (42) for applying a force F2 on the said head (82) of the said cap(8), typically varying from 500 N to 1500 N after the said screwing stepand during all or part of the said crimping step.
 6. Device according toclaim 5, in which the said means for applying the said force F2 istypically activated before the said rollers (41) are applied in contactwith the said skirt in order to crimp the said skirt (80), so as toaxially compress the said cap (8) in contact with the said neck (70) andits sealing ring, particularly when the said cap (8) comprises acompressible seal (81) to be compressed before the crimping step inorder to seal the said cap (8) on the said neck (70).
 7. Deviceaccording to claim 4, in which the said capping head (2) comprises: a) asupport C3 (3), typically cylindrical, solidarised to a fixed frame(10), capable of turning about the said axis of rotation (20) with thesaid rotation speed Ω typically predetermined and possibly constant, andmoving in the axial direction with respect to the said neck (70) with anaxial displacement D3, b) a coaxial tubular body C2 (4) internal to thesaid support C3 (3) and coaxial with it, but capable of moving axiallywith respect to the said support C3 (3) with an axial displacement D2,the said support C3 (3) comprising a lower stop (30) to limit the axialdisplacement of the said tubular body C2 (4) and applying a force F2 onthe said tubular body C2 (4), typically using a spring R2 (42), c) acentral body C1 (5), coaxial with the said tubular body C2 (4),typically hollow, solidarised to the said tubular body C2 (4) for thesaid displacement D2 typically by means of a set of bearings, typicallyneedle bearings (45), the said tubular body C2 (4) forming a hub for thesaid central body C1 (5) acting as an axle, d) a means for partialcoupling of the said tubular body C2 (4) and the said central body C1(5) in rotation, rotation of the said tubular body C2 (4) only causing arotation of the said central body C1 (5) during the said screwing step,rotation of the said central body C1 (5) possibly being interrupted bythe development of an opposing torque C at the end of screwing, e) thesaid central body C1 (5) comprises a bearing part C0 (6) that will causerotation of the said cap (8) and move axially with respect to the saidcentral body C1 (5) with a displacement D0 typically corresponding tothe height of the (51) for the said bearing part (6) and a spring R0(60) applying a force F0 on the said bearing part C0 (6) so as toprovide coupling of the said capping head (2) through the said bearingpart C0 (6) and the said cap (8) in rotation, and to form the saidscrewing means, f) the said arms or lifting beams (40) of the saidcrimping means are axially fixed to the said tubular body C2 (4) and canbe rotated due to a secondary rotation axis (44) typically fixed to thesaid tubular body C2(4).
 8. Device according to claim 7 in which thesaid crimping means includes a cam (32) axially fixed to the saidsupport C3 (3), each of the said typically rigid arms (40) comprising anupper part (400) typically provided with a caster or a wheel or asliding pad (401), and a roller support arm (402) supporting the saidroller (41), such that the said second displacement causes a temporarycooperation of the said cam (32) and the said wheel or pad (401),bringing the said roller (41) closer to the said neck (70) for the saidcrimping.
 9. Device according to either claim 7 in which the saidsupport C3 (3) of the said capping head (2) is solidarised to an arm(12), typically horizontal, and is free in rotation with respect to thesaid arm (12), the said support C3 (3) and the said arm (12)respectively forming an axle/hub assembly, the said arm (12) possiblyacting as a support for a motor forming the said rotation means (13)capable of driving the said support C3 (3) in rotation.
 10. Deviceaccording to claim 9 in which the said arm (12) and the said fixed frame(10) cooperate, typically using a vertical column (14) so as to assurethe said axial displacement D3 of the support C3 (3) by translation ofthe said arm (12) in a vertical plane, typically by means of anauxiliary motor (11) acting as an axial displacement means.
 11. Deviceaccording to claim 9 in which the said arm (12) is placed onboard arotary turret and forms part of a set of n capping heads (2), where ntypically varies from 2 to 12, the supports C3 (3) being engaged to acentral gearwheel to rotate the said supports C3.
 12. Device accordingto claim 7, in which the said partial rotational coupling means of thesaid tubular body C2 (4) and the said central body C1 (5) is a magneticor electromagnetic coupling, typically by means of facing magnets (43,50) supported by the said tubular body C2 (4) and the said central bodyC1 (5).
 13. Device according to claim 7 in which, at the end of thescrewing step, the said bearing part C0 (6) can be brought into contactwith the said upper stop (51) so that the said central body C1 (5) andthe said tubular body C2 (4) can transmit the said force F2 to the head(82) of the said cap (8).
 14. Device according to claim 1, in which therotation speed Ω and displacement speed V of the said capping head (2)during the said first displacement are slaved so as to satisfy therelation V=Hf.Ω/N so as to synchronise rotation of the said cap (8) andlowering it onto the neck (70) during the said screwing step, typicalvalues of Hf, Ω and N being between 5 mm and 20 mm for Hf, between 150rpm and 500 rpm for Ω, and between 10 and 25 turns for N.
 15. Method ofcapping a bottle using the capping device (1) according to claim 1, inwhich the said capping head (2) screws and crimps a screw cap (8) on thethreaded neck (70) of the said bottle or receptacle (7) and in which thesaid bottle (7) having firstly being brought facing the said head,typically by horizontal step by step displacement, or possiblycontinuous displacement, of the said bottle (7) and alignment of thesaid rotation axis (20) and the axis of symmetry (71) and held still fora time T corresponding to one capping cycle, the said head is subjectedto a cyclic movement with duration T with respect to the said neck (70)typically including lowering of the said head from a high point to a lowpoint, with a lowering time Td of the said head during which the saidcap was firstly procured and placed on the said neck, the said screwingis carried out first during a time Tdv followed by the said crimping fora time Tds, the said lowering time Td being approximately equal to thetime necessary to perform the said first and second displacements,followed by a rise time Tr of the said head, the said bottle after beingcapped being displaced and replaced by another bottle to be cappedtypically when the said head is at the said high point.
 16. Methodaccording to claim 15 in which the said cyclic movement of the saidcapping head (2) is a sinusoidal movement typically obtained bycooperation of a connecting rod and a crank.
 17. Method according toclaim 15 in which the said cyclic movement of the said head (2) is acontinuous circular movement typically obtained using a cam.
 18. Methodaccording to claim 15 in which the said cyclic movement of the said headis a movement composed of linear parts at constant speed, typicallyobtained with hydraulic jacks.
 19. Method according to claim 18 in whichthe rise time Tr may be shorter than the lowering time Td, and typicallyless than half as long.